Method of pleating film



Patented Sept. 20, 1938 UNITED STATES PATENT OFFICE.

Celluloid Corporation, a.

Jersey corporation of New No Drawing. Original application May 2, 1935,Serial No. 19,384. Now Patent No. 2,025,568. Divided and thisapplication September 21, 1935,

Serial No. 41,629

13 Claims.

, This invention relates to a permanently pleated or shaped sheet, filmor foil containing a derivative of cellulose and to the articles madefrom same, and relates more particularly to sheet material so processedthat, when pulled out and released, it snaps back to the shape it hadprior to being pulled out.

This application is a division of my co-pending application S. No.19,384, filed May 2, 1935 which has matured into Patent No. 2,025,568.

An object of the invention is the economic and expeditious production ofpleated sheets, films or foils containing derivatives of cellulose andthe articles made from same. A further object of the 15 invention is thepreparation of materials suitable for decorative purposes which aresubstantially moistureproof and resistant to weather changes. Otherobjects of the invention will appear from the following detaileddescription.

As is known, pleated. sheeting materials of paper, fabric, etc., havebeen used in the lamp.

shade industry. These materials have not been entirely satisfactory.When employing a fabric the pleats of same had to be stitched in to holdthem in shape and after stitching'it was impossible to place the sameover irregular lamp shade forms or other articles. Where paper,

parchment and like materials in pleated form' were used, the pleats whenonce pulled out,

either intentionally or accidentally, rendered the material unfit forits intended purpose as it no longer hugged and fit the form butremained permanently distorted. By employing this invention, which ingeneral may be described as pleating thin sheets or foils of aderivative of material so, that it may possess a degree of A strengthsuitable for the purpose intended.

A further advantage of thearticle produced in accordance with thisinvention is that it is practically moistureproof and resistant toweather-changes. Thus, the material may be used in moist or damp placesor extremely dry places without any substantial change in its form beingeflected, such as, for example, the release' of the pleats or thedrooping of the material in damp places, or the cracking and splittingof the material in extremely dry places- Another desirable property ofthe material produced in accorgiance with this invention is that anarticle made therefrom may be sponged, washed and otherwise cleanedwithout damage thereto since there can be no removal of the pleats orstreaking of the material due to the action of the dirt and the fluidused in cleaning thereof.

' This material made in accordance with this invention also has theadvantage over paper, fabrics and parchment, etc. in that it has no napor filament ends to catch dust and other materials such as normallycollect on lamp shades of paper, parchment and textile fabric. Thesurface of the new material is smooth and does not act as a trap fordust particles and lint.

A further advantage of this invention is that although the sheetingmaterial may be very thin and light in weight it is very durable evenwhen pleated, and unlike paper, parchment or other sheeting materials,is not readily torn. Not only is the material durable but it alsoretains its pleated shape under all atmospheric conditions, thusoffering a marked advantage over silk and other fabrics whose edges mustbe sewed together to maintain the pleat.

Pleated sheets or foils of derivatives of cellulose exhibit a uniquerubber" elasticity. They can be stretched an appreciable distance beforepermanent deformation takes palce. In making a lamp-shade, for example,a rectangular blank of pleated sheeting material containing a derivativeof cellulose is cut and the two ends are cemented together with anysuitable cellulose ester film cement. When this sheet which is now intubulartform is stretchedover the frame of a lamp shade, it will befound that the formed sheet-hugs the frame tightly and conforms to itsshape even in the case where the form is concave. This is a distinctadvantage, since it not only makes for economy of material but alsoinsures permanency of form. Lamp shade blanks, as heretofore made, wereusually stamped out in irregular or circular form. However, in the caseof pleated sheets containing derivatives of cellulose, the blanks may berectangular in form regardless of the shape of the frame they are tofit, thereby resulting in very little wastage in the operation ofcutting. The elasticity of the known that there is usually a lengthshrinkage of about 80 per cent when placing the pleats in the material,which pleated product may be pulled out or stretched to substantiallyits original length and upon being released returns to its shrunkenlength. In otherwords, a strip of foil 100 inches long when pleated inpleats of about $4; of an inch measures only 20 inches in length. Theresultant elasticity, resiliency or tendency to return to its shortlength when the pleated foil is stretched is profitably utilized incovering and wrapping many articles of irregular shape. 'Allotherproducts such as paper, parchment, sheets of gelatin, sheets'oiregenerated cellulose,

- and mus, of organic derivatives of cellulose, or-=- fabric, etc., donot. exhibit this remarkable stretching characteristic which adapts thematerial of the present invention to the'use of wrapping, covering oracting as a decorative material on various articles of irregular shape.

While the material of this invention may be of crystal cleartransparency, it may also be attractively decorated with designs-or itmay be embossed, printed, lacquered. etc. Further, the

base material may contain various effect materials which alter itstransparency thus producing a material which may be translucent, opaqueor mottled. These transparent, translucent and opaque effects may beall-Jover or merely local. Moreover, these various effects may beproduced in the material without adding materially to the weight thereofand without otherwise altering the physical characteristics of the clearproduct. The articles made therefrom are extremely light in weight, areodorless and are permanent as to their shape, color, transparency, etc.

A distinct advantage of the material of the present invention is thatwhen using the crystal clear product it allows for the transmission of,

ultra-violet light rays. This quality is of great advantage in. theemployment of the material as lamp shades, screens, etc. I

In accordance with my invention, I prepare a sheet, film or foilcontaining a derivative of cellulose with or without a. plasticizer, byinserting bends or'pleats in the sheet, film or foil under heat andpressure so that they are substantially permanent. The pleating of thesheet material in this manner results in a pleated product which may bepulled out to straighten out the pleats therein and while under thisstress the materialexerts a strong force to resume its pleated shape,giving the effect of an elastic-material. Inaccordance-with thisinvention, I form articles by stretching this pleated material oversuitable forms in order to produce lamp shades, screens,- fiower potcovers and other articles. v

Any suitable thermoplastic sheet, film or foil made of or containingderivatives of cellulose may be'pleated, or employed as the basematerial in forming the pleated sheets. Sheets, films ganic. derivativesof cellulose mixed with'plasticizers, organic derivatives of cellulose.mixed with or without plasticizers, with effect materials may beemployed. The'sheet, film or foil which is pleated may be of anysuitable thickness, for instance, from .0005 inch to .015 inch,preferably from .0008 inch to .003 inch. Although cellulose,

acetate is the preferable organic derivative of cellulose to be employedas the base of sheet material, other suitable organic derivatives ofcellulose may be employed such as the organic acid esters of celluloseand the cellulose ethers. .-amples of the organic acid esters ofcellulose are cellulose formate, cellulose butyrate and cellulose,propionate while examples of ethers are methyl cellulose, ethylcellulose and benzyl cellulose. While organic derivatives of cellulose,suchascellulose acetate are preferred, cellulose nitrate foils and filmsmay also be satisfactorily pleated with heat and pressure. .After thethermoplastic sheet may be given a denitratlng treatment with. .81!

kaline solutions such as caustic soda, sodium hy-- drosulphide, etc. I

The sheet stock to be pleated preferably contains from 5 to per cent ormore, based on the weight of the cellulose derivative present, of

ticizer employed depending upon thetype and amount of effect materials,ifany, contained in the sheets. Although any suitable plasticizer may beemployed, for forming crystal clear thin organic derivative of cellulosesheets having especially high resiliency, it is preferable to employfrom 5 to 30 per cent based on the weight of the organic derivative ofcellulose present of dibutyl phthalate.

The plasticizer may be any suitable one for the particular cellulosederivative or mixture of cellulose derivatives employed. Theplasticizers may be any of the high boiling solvents or softeningagents, as for example, aryl sulphonamides, e. g., para-ethyl-toluolsulphonamide; the aikyi phthalates, e. g., dimethyl phthalate; thedialkyl tartrates, e. g., dibutyl tartrate; thealkoxy esters ofpolybasic organic acids, e. g., dimethoxy ethyl phthalate; the polybasicacid esters of the mono alkyl ethers of polyhydric alcohols, e. g.,diethylene glycol ethyl ether ester of phthalic acid; the

alkyl esters of phosphoric acid, e. g., triethyl glycol phosphate thearyl esters of phosphoric acid, e. g., tricresyl phosphate; the mixedalkyl and'aryi phosphates,- e. g., ethylglycol dicresyl phosphate, andcamphor.

The sheet stock which is to be-pleated may contain any suitable effectmaterials which effect materials may be employed to alter thetransparency, resiliency, color, handle, fluorescence or otherproperties of the material. Thus, such effect materials as pigments,filling materials, dyes or lakes, fire retardants, plasticizers,water-proofing agents, etc., may be employed. Examples of fireretardants are beta chlornaphthalene, triphenyl phosphate, tricresylphosphate, etc. Ex-

' amples of filling materials'that may be employed the film, foil orsheet, or by applying the same to has been formed'into pleats, thepleated sheet the formed sheet in the presence of suitable sol vents orswelling agents. I

The sheet, film or foil may be pleated in any suitable manner, forinstance, by running the same through a fabric pleating machine afterhaving placed on either or both sides of the sheet a thin sheet of paperas a guide and/or protection. The stock may be conditioned prior topassing it through the pleating machine by passingthe same through asteam chamber, a chamber 7 containing solvent vapors for the material ofthe stock, through a heated chamber, or through a heated liquid such aswater. The material may be shaped into any desired form of pleat. 1prefer, however, that the space betweenthe bends of the material uponitself be of the order of less than one-half inch. Sheets having pleatsofabout o'ne-eighthinch between bends has been found to be highlysuitable for lamp shades, and similar uses. 1 However larger or smallerpleats may be employed. 'The material may be formed into accordionpleats, box pleats, crystal pleats or any suitable pure plasticizer, theamount of plasother types of pleats, orthe material may have more thanone type of pleat formed therein.

when inserting pleats inthe sheet, film or foilit is preferable to setthe pleat in the material by roll or other device having a coolingmedium circulating therein, for the purpose of setting the bends in thematerial prior to any considerable amount of handling of the material.By this means the micelles in the base material are rearranged such thatthe bends forming the pleats are made permanent or substantially so,giving to the material the property of exerting a force such that whenpulled out it tends to return to its tightly pleated condition.

This pleated material may also be formed into articles, such ascoverings for flower pots, hoods for protecting flowers, plants, etc.,hat bands,

brims, ribbons, etc. Straw hats made with pleated sheets either alone orcomposited with suitable base materials, will be found light,waterproof, washable, etc. The pleated material finds other uses, suchas for bracelets, eye shades, novelties, curtains, blinds, screens,garters, belts, cake receptacles, candy wrappers, corsage ribbons, cardindex holders, tabs, etc. The pleated material may be stretched over anyobject having sufllcient rigidity to support same. For instance,metallic wire lamp shade forms, clay flower pots,

whalebone articles and wearing'apparel, etc., may

be employed as the base over which the pleated material is stretched.

The pleated material may be readily cemented at the seams to make astretchable tubing for countless applications. The cement may be appliedto the edges of the pleated' material to hold or weld it to metal framessuch as lamp shade frames and the like. Thus in the case of concave lampshades, when the pleated cylinder "stocking is stretched over the frame,there will be a tendency of this material to spring upwards unless it isattached to the frame either by welding it thereto with cement orbinding it thereto with a suitable tape or braiding. Suitable tape orbraiding may be formed or molded from organic derivatives of celluloseor woven from textile materials and the same may be attached'to thepleated sheet material by applying a solvent or cement to the pleatedmaterial and pressing the tape or braiding into the softened material.

In forming covers for various articles, the pleated sheet, being plasticand moldable under heat and pressure, may be ironed smooth at placeswhere flatness is desired. This is a property characteristic only ofthis material and is not found in any other type of cover now employed.This property allows for very distinctive effects made by heat-sealingcertain areas of the pleated materialwhich have previously been softenedwith solvents, etc. The subsequent crinkling that may take place, theresult of using softening solutions and/or heat, produces a. verydesirable effect. Further, the property of it being possible to removethe pleats from certain areas of the materials allows for covers, notonly having distinctive eflects, but which may be shaped to enhance theutility of the material where the utility of the material would requirea flat surface not containing pleats, for example, the bottom part oivcovers for containers, parts of lamp shades that are to be placedbetween a wall and lamps or any other limited space wherein the pleatswould give rise to too thick a material.

Two or more layers of the pleated material having the same size pleatsor diflerent size pleats may be imposed one upon the other with orwithout additional material between the layers. The

pleats in the two layers'may be' caused to run parallel or they may berun at right angles to each other to produce novel effects,particularly,

when the different layers have variegated color effects. Thepleatedmaterial may also be stretched fan shaped and the fan may becemented to glass or other base material to yield ornamental radiatingeffects suitable for placing at the back of wall lights, lights onmirrors and the like. This use of .the material produces a most strikingappearance when lacquered with pearl essence.

Prior to pleating the film or foil, the same may be laminated withpaper, silk and cellulosic fabrics, cellulosic sheet material, and otherrelatively flat, thin materials that may be lacking in that propertythat gives the elastic-like springiness to the pleated fllms containingan organic derivative of cellulose. The film of foil containing anorganic derivative of cellulose may be laminated with the othermaterials by cementing agents with or without heat and pressure.Examples of cementing agents that may be employed are those described inU. S. Patents Nos. 1,981,141 and 1,835,619. Thus an elastic-likematerial may be formed that has a cloth-like appearance by cementing afabric to one or both sides of a fllm' containing an organic derivativeof cellulose and pleating the same in the presence of heat and underpressure. Also the fllmor foil containing an organic derivative ofcellulose may be-laminated, with a film or foil having an embossedsurface in imitation of crepe or other design.

A furthermodiflcation may be formed by laminating an edging, such as afold of paper, metal foil, cotton fabric, rayon fabric, celluloseacetate fabric or transparent sheet material of regenerated orreconstituted cellulose, to the sheet material containing an organicderivative of cellulose which itself may be laminated as describedabove. After laminating the sheet material with the other materials thesame may be pleated. By this means both ornamental and protectiveedgings may be placed on the material. An example of this modificationis in pleated collars for women or children, which are edged with afabric to reduce the tendency of the sharp corners of the pleatedmaterial to irritate the skin that they contact.

The material, regardless of the shape in which it is formed, may besprayed, brushed, dipped or otherwise treated with lacquers, varnishes,etc., in the form of solid,colors, variegated colors in patterns, orflowers and other designs may be stencilled or painted on the same. Thisproduces, when using the crystal clear material, novel effects notattainable by the use of any other material now known in the art. i

In theclaims the termfisheets is intended to include sheets, films andfoils that may be formed -by any suitable method. For'instance, sheets,i'ormed by extruding a solution of an organic derivative of cellulose,in a volatile solvent, through suitable orifices into an evaporative orprecipitating medium or they may be formed by casting the solution upona surface, preferably a film casting wheel or the like.

It is to be understood that the foregoing detailed description is merelygiven by way of illustration, and many variations may be made thereinwithout departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patentis:

l. A method of making a new article of manufacture, which comprisessubjecting a continuous thin film of an organic derivative ofcellulose'hav ing a thickness of from .002 to .005 of an inch to atemperature at which it is softened, forming pleats in the softenedfilm, and then immediately cooling it to a temperature at which itassumes a set condition.

2. A method of making a new article of manufacture, which comprisessubjecting a continuous thin film of cellulose acetate having athickness of from .002 to .005 of an inch to a temperature at which itis softened, forming pleats in the softened film while subjecting it toa temperature at which it is softened, said temperature being maintainedfor a short period after the pleating operation, and then immediatelycooling it to a temperature at which it assumes a set condition.

3. A method of making a new article of manufacture, which comprisessubjecting a continuous thin film of an organic derivative of cellulosehaving a thickness of from .002 to .005 of an inch to a temperature atwhich it is softened, forming pleats about /a of an inch in width insaid film while subjecting it to a temperature at. which it i issoftened, and then immediately cooling it to a temperature at which itassumes a set condition.

4. A method of making a new article of manufacture, which comprisessoftening a continuous thin film of cellulose acetate having a thicknessof from .002 to .005 of an inch by heat, forming pleats about of an inchin width in said film while subjecting it to a temperature at'which itis softened, and then immediately cooling it in pleated form to atemperature at'which it assumes a set condition. f

5. A method of making a new article of manufacture, which comprisessoftening a continuous thin film of cellulose acetate having a thicknessof about .003 of an inch, forming pleats about 2; of an inch in width insaid film while subjecting it to a temperature at which it is softened,said temperature being maintained for a'short period on the pleatedsheet, and then immediate- 1y cooling the pleated sheet to a temperatureat which it assumes a set condition.

6. A method of making a new article of manufacture, which comprisesforming pleats in a continuous thin film of an organic derlvativeofcellulose containing from 5 to 30% of a plasticizer for said organicderivative of cellulose and. having a thickness of from .002 to .005 ofan inch, while subjecting it to a temperature at which it is softened,-and then immediately cooling it in pleated form to a temperature atwhich it-assumes a set condition.

7. A method of making a new article of manufacture, which comprisessoftening a continuous thin film of cellulose acetate containing aplasticizer for said cellulose acetate and having a thickness of from.002 to .005 of an inch, formingpleats about of an inch in width in saidfilm while subjecting it to a temperature at which it is softened, andthen immediately cooling it to a temperature at which it assumes a setcondition.

8. A method of making a new article of manufacture, which comprisessoftening a continuous thin film of cellulose acetate containing from 5to 30% of a plasticizer for said cellulose acetate and having athickness of about .003 of an inch by heat, forming pleats about of aninch in width in said film while subjecting it to a temperature at whichit is softened, and then immediately cooling it to a temperature atwhich it assumes a set condition.

9. A method of making a new article of manufacture, which compriseslaminating a. continuous thin film of an organic derivative of cellulosewith at least one other flexible sheet, softening said composite sheet,forming pleats in the composite sheet while subjecting it to atemperature at which the cellulose derivative issoftened, and

then immediately cooling the pleated composite sheet to a temperature atwhich the cellulose derivative assumes a set condition.

10. A method of m'akinga new article of manufacture, which compriseslaminating a continuous thin film of cellulose acetate with at least oneother flexible sheet, softening said composite sheet by heat, formingpleats in the composite sheet while subjecting it to a temperature atwhich the cellulose acetate is softened, maintaining said temperature onthe'pleated composite sheet for a short period, and thenimmediatelycooling the pleatedcomposite sheet to a temperature at which thecellulose acetate assumes a set condition. y

11. A method of producing material for use in making a lamp shade, whichcomprises softening a continuous thin film of an organic derivative ofcellulose having a thickness of from .002

to .005 of an inch by heat, forming pleats of about A; of an inch inwidth in said film while subjecting it to a temperature at which it issoftened, immediately cooling the pleated film to a temperature at whichit assumes a set condition, cutting a rectangular blank from saidpleated film material, and joining two edges of the blank with asuitable cement.

12. A method of producing material for use in making a lamp shade, whichcomprises softening a cellulose acetate continuous thin film having athickness of from .002 to .005 of an inch, forming pleats of about of aninch in width in said film while subjecting it to a temperature at whichit is softened, immediately cooling the pleated film to a temperature atwhich it assumes a set condition, cutting a rectangular blank from saidpleated film material, and joining two edges of the blank with asuitable cement.

13. A method of producing material for use in making a lamp shade, whichcomprises softening by heat a cellulose acetate continuous thin filmcontaining a plasticizer for'the cellulose acetate and having athickness of about .002 to .005 of an inch, forming pleats of about /3of an inch in width in said film while subjecting it to a temperature atwhich it is softened, immediately cooling the pleated. film to atemperature at which it assumes a set condition, cutting a rectangularblank from said pleated film material, and joining two edges of theblank with a suitable cement.

- JOSEPH H. BROWN.

